The seller shall deliver to the buyer a copy of the retail installment contract signed by the seller. Any acknowledgment by the buyer of delivery of a copy of the contract must be printed or written in a size equal to at least 10 point bold type and, if contained in the contract, must appear directly above the legend required above the buyer’s signature by Section 3. The buyer’s written acknowledgment of delivery of a copy of the contract conforming to the requirements of this Act is conclusive proof of that delivery and of compliance with this Section in any action by or against an assignee of the contract without knowledge to the contrary when he purchases the contract. Until the seller delivers a copy of the contract to him, a buyer who has not received delivery of the goods or has not been furnished or rendered the services has the right to cancel his agreement and to receive a refund of all payments made and a return of all goods traded in to the seller on account of or in contemplation of the contract or, if those goods cannot be returned, the value thereof. However, this Section shall not apply when merchandise has been specially ordered or custom made to the specifications of the purchaser and evidence of such order is provided the seller.